1. Field of the Invention
This invention pertains to the related fields of computer aided design (CAD) and computer graphics. More specifically, this invention relates to a method for creating a computer rendered image of a three-dimensional object.
2. Background Description
One of the objectives of computer aided design systems is the realistic rendering of an image of a three-dimensional object. By imparting greater realism to computer generated images, a designer is better able to visualize the three-dimensional structure and appearance of an object without actually constructing a physical prototype. Prior art computer graphics systems provide the ability to model a three-dimensional object and rotate it so that a two-dimensional image of the object may be viewed from any direction.
A field in which visualization of objects with applied surface texture is particularly important is fashion design. A number of systems have been developed that allow a fashion designer to apply different fabric textures and patterns onto a computer generated image of a garment. Such systems permit the designer to visualize a garment made from the selected fabric in a realistic manner, including the distortions naturally introduced by the drapes and folds of fabric as it would appear on an actual three-dimensional garment. A system of this type is described in U.S. Pat. No. 4,888,713 issued to Falk. In this particular system, an operator applies an orthogonal mesh to an image of a garment and, using a variety of CAD tools, distorts the mesh so that the mesh appears to have the proper perspective, including wrinkles and folds of the fabric. Texture is then applied using conventional mapping techniques such as described in the above-referenced articles.
An improved texture mapping system with particular application to the fashion design industry is described in this inventor's copending application Ser. No. 07/579,884, filed Sep. 7, 1990 now U.S. Pat. No. 5,333,295 and entitled "Method and Apparatus for Mapping Surface Texture", the disclosure of which is incorporated herein by reference. This system allows an operator to model a surface of an object such as a garment in three dimensions, but depends on the operator's skill in visualizing the perspective appearance of the desired three-dimensional structure.
The present invention provides the operator with a stereoscopic display so that a full three-dimensional view of the object to be modelled is presented. The object may thus be "sculpted" in three dimensions.